Please this:
Issue
The Object Properties window has been dragged off screen and you cannot retrieve it.
Solution
There are two methods of making the Object Properties window visible
again.
Method #1
Edit the Windows® registry:
Warning!
Problems caused by improperly editing the Windows registry could render
your
computer operating system unusable. Microsoft provides a wealth of
critical information that you need to know about the registry in the Microsoft
Knowledge Base at http://support.microsoft.com/support.
Use the Microsoft® Registry Editor only at your own risk and only after
backing up the registry as well as the system.dat and user.dat files as
outlined for your operating system in the Microsoft Knowledge Base and in
the Technical Solution TS66513. Additional information about the registry
is also available in the Help topics in the Microsoft Registry Editor
Start the Registry Editor and locate the following subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Autodesk\AutoCAD\R15.0\ACAD-1:409\DockedTools
Edit the entry with the value name {6D32A2D9-832E-11D2-A83C-0060B0872C0B}.
For a 1024 x 768 pixel screen resolution, use value data of 3 689 58 337
569 1 to set the Properties window to the docked position.
Exit the Registry Editor.
Method #2
On the Start menu (Windows), click Settings > Taskbar & Start Menu.
In the Taskbar and Start Menu Properties dialog box, select the Auto Hide
check box and click OK.
See Also
Object Properties Manager window is not displayed"